1. Field of the Invention
The present invention relates to an illuminating wrist exerciser, and in particular to a wrist exerciser that features rotation based power generation and includes parts for high-performance magnetic-field induced power generation and light emission.
2. The Related Arts
Wrist exercisers are widely known in exercising and training wrist-related muscles, especially for rehabilitation and therapy purposes. Examples of the wrist exercisers are illustrated in Taiwan Utility Model No. 135058 and U.S. Pat. No. 5,800,311, wherein a wrist training sphere that is operated with rotary motion thereof is provided with structures of power generation and light-emitting diode so that forcibly pulling a rope wound around a rotor to initiate rotation of the rotor causes electromagnetic interaction in a face-to-face manner between windings mounted to the rotor and magnets mounted to a casing that houses the rotor to induce electrical power for lighting the light-emitting diodes. Such structures add extra functions and surface decorations to the wrist training devices.
However, in the conventional structures of power generation and lighting elements of the known wrist training devices, the electromagnetic interaction between the magnets and the windings suffers insufficiency of power generation due generally to a large magnet gap and high magnetic leakage, which leads to relatively high magnetic reluctance, high magnetic leakage, and relatively small magnetic flux in the electromagnetic interaction, and consequently, when the rotor is in a low speed rotation, the lighting performance of the light-emitting diodes is poor, and such a problem is only overcome by increasing the rotational speed of the rotor.
In addition, other prior art references are also known, such as Taiwan Utility Model No. 580942, which discloses an “illuminating wrist exerciser ball” having a construction similar to those disclosed in Taiwan Utility Model No. 135058 and U.S. Pat. No. 5,800,311. A difference resides in that magnetic elements are provided, on surfaces thereof, alternating and adjacent positive and negative magnetic zones (namely a plurality of opposite polarities of “N” and “S”) and a slide ring and an extension of a brush are set corresponding to the alternating positive and negative magnetic zones of the magnetic elements, whereby by means of the corresponding arrangement of the slide ring and the brush, windings and light-emitting diodes are connected to generate electrical power to light the light-emitting diodes. This arrangement similarly suffers the problems of large magnet gap, high magnetic reluctance, and high magnetic leakage and consequently, poor performance of power generation and lighting of light-emitting diodes. Further, the alternating arrangement of multiple positive and negative magnetic zones makes the magnetic elements and the construction of the slide ring and the brush complicated, which causes difficult in assembling and maintenance, leading to increased costs of manufacturing and maintenance. This is adverse to the industry. Further, the slide ring, the brush, and an internal support ring induces frictional resistance, high level noise and part wearing during the rotation of the rotor, and eventually reducing the operation performance and the lifespan of the wrist training devices.